Orexigen obesity drug meets goals in 3 studies

NEW YORK 
Orexigen Therapeutics Inc. said Monday that its obesity-drug candidate Contrave met its main goals in three late-stage clinical trials, and also surpassed a Food and Drug Administration requirement for effectiveness.

Patients who took Contrave had significantly greater weight loss than those who took a placebo, and the drug reduced other risk factors like waist circumference, the company said. For diabetes patients, the drug also diminished blood sugar levels.

The San Diego-based company said it plans to seek FDA approval for Contrave in early 2010.

Orexigen said the drug also tempered food cravings and allowed patients to better control their eating. Its shares jumped $1.51, or 26.5 percent, to close at $7.20 Monday.

In the two trials with non-diabetes patients, Orexigen said 48 percent and 56.3 percent of patients, respectively, reported weight loss of at least 5 percent. That compared to 16.4 percent and 17.1 percent for the placebo patients. That more than met FDA testing guidelines that require at least a third of patients must lose at least five percent of their body weight. At least twice as many patients must reach the 5 percent goal compared with those who take a placebo.

In those trials, the Contrave patients had mean weight loss of 8.1 percent and 8.2 percent, or 17.6 pounds and 17.5 pounds. In the diabetes trial, 44.5 percent of patients lost at least 5 percent of their weight after 56 weeks, compared to 18.9 percent of patients who took a placebo. Contrave patients reduced their blood sugar by 0.6 percent, compared to 0.1 percent for the placebo group.

The three trials each lasted 56 weeks. The non-diabetes trials involved 1,742 patients and 1,496 patients, respectively, while 505 people with type 2 diabetes participated in the third trial.

Mean weight loss in the diabetes trial was 5.9 percent, or 13.5 pounds, compared with 2.2 percent, or 5.1 pounds.

The studies tested Contrave32, which combines bupropion, a drug used against depression and smoking habits, with naltrexone, which is used to fight alcoholism and opiate addiction. Orexigen CEO Mike Narachi said the drug "targets behavior and reward pathways in the brain."

Dennis Kim, who leads Orexigen's obesity and metabolic-disorders unit, said Contrave is "the first drug I'm aware of that addresses cravings in terms of obesity."

Orexigen has two other doses of Contrave: Contrave16 contains a lower dose of naltrexone, and Contrave48 has more of the drug.

Its rivals, Arena Pharmaceuticals Inc. and Vivus Inc., also are trying to bring their own obesity drugs to market.

Orexigen said the data show Contrave is safe. The most serious side effects in the trial included a gallbladder infection and seizure, which affected two patients each. One patient reported heart palpitations, while another experienced poor circulation in the limbs and one had vertigo. The most common side effects were nausea, constipation and headache.

Orexigen said it is preparing to file for FDA approval on its own, but is seeking a partner to bring Contrave to the primary-care market and to overseas markets.

The FDA has created two benchmarks for obesity-drug candidates, and all treatments must meet at least one to be approved. Contrave surpassed one of the two. The other benchmark requires that a study show a difference in weight loss of at least 5 percent between the drug candidate and a placebo. A previous late-stage trial of Contrave was designed with that goal in mind, but it was unsuccessful, as the difference in weight loss was 4.2 percent. Orexigen reported those results in January, and its stock plunged.